Plant species sensitivity distributions for ozone exposure

Area of Science:

• Environmental toxicology
• Ecology
• Plant science

Background:

• Ozone is a significant air pollutant impacting natural vegetation.
• Existing critical levels for ozone may not adequately protect plant communities.
• Species Sensitivity Distributions (SSDs) offer a robust framework for ecological risk assessment.

Purpose of the Study:

• To derive Species Sensitivity Distributions (SSDs) for ozone exposure on different plant functional groups.
• To calculate and compare SSD-based critical ozone levels with existing standards.
• To estimate the potentially affected fraction of plant species in Northwestern Europe under ambient ozone concentrations.

Main Methods:

• Construction of SSDs for trees, annual grassland, and perennial grassland species using species-specific exposure-response data.
• Application of SSDs to derive critical levels for each species group.
• Spatially explicit estimation of the potentially affected fraction of plant species based on ambient ozone data.

Main Results:

• SSD-based critical levels for ozone were found to be lower than current critical levels.
• Conventional critical levels for ozone were associated with 8-20% affected plant species.
• Spatially explicit estimates of affected plant species fractions were successfully calculated for Northwestern Europe.

Conclusions:

• The SSD approach is effective for deriving critical ozone levels for natural vegetation.
• SSDs provide a more conservative and protective estimate of ozone impacts on plant communities.
• This methodology can be used to assess ozone risks across various plant communities and geographical areas.